Parallel pole circuit breaker

ABSTRACT

Four single-pole circuit breakers are stacked side by side with an internal strap connecting line terminals of a first pair of adjacent circuit breakers and another internal strap connecting line terminals of a second adjacent pair of circuit breakers. A single line terminal stab is provided for each pair of circuit breakers, with each line terminal stab having a portion inside a circuit breaker housing and a portion extending externally thereof. The stabs are spaced apart by the center-to-center distance between adjacent pole units to engage differently phased cooperating stabs in a panelboard. The load terminals of each pair of circuit breakers are electrically connected and are provided with a single wire grip positioned in alignment with the abutting surfaces of the circuit breakers in each pair. The wire grip housing is secured by a snap-on-type connecting means and is disposed so as to prevent tampering with the load terminal connections of the individual circuit breakers.

United States Patent [72] Inventor Carl E. Gryctko Haddon Heights, NJ. [21] App1.No. 874,776 [22] Filed N0v.7,1969 [45] Patented Apr. 6, 1971 [73] Assignee I-T-E Imperial Corporation Philadelphia, Pa.

[54] PARALLEL POLE CIRCUIT BREAKER 10 Claims, 18 Drawing Figs.

[52] U.S.Cl 200/168, 317/119 [51] Int.Cl H0lh9/02 [50] FieldofSearch 200/168 (A),168(S);317/119 [56] References Cited UNITED STATES PATENTS 3,263,132 7/1966 Bangert,Jr. 200/168(A) 3,271,549 9/1966 Gelzheiser 317/119(X) 3,333,078 7/1967 Gelzheiseretal... ....200/16 8(A)(X) 3,333,157 7/1967 Stokes 317/119 3,349,290 10/1967 Casey 3,403,299 9/1968 Mrowkaetal.

Primary Examiner-H. 0. Jones Attorney-Ostrolenk, Faber, Gerb & Sofi'en ABSTRACT: Four single-pole circuit breakers are stacked side by side with an internal strap connecting line terminals of a first pair of adjacent circuit breakers and another internal strap connecting line terminals of a second adjacent pair of circuit breakers. A single line terminal stab is provided for each pair of circuit breakers, with each line terminal stab having a portion inside a circuit breaker housing and a portion extending externally thereof. The stabs are spaced apart by the center-to-center distance between adjacent pole units to engage differently phased cooperating stabs in a panelboard. The load terminals of each pair of circuit-breakers are electrically connected and are provided with a single wire grip positioned in alignment with the abutting surfaces of the circuit breakers in each pair. The wire grip housing is secured by a snap-on-type connecting means and is disposed so as to prevent tampering with the load terminal connections of the individual circuit breakers.

PATENTEI jAPR slsm 3573, 415

SHEET 2 UF 6 INVENTOR. 451 5 em rrra PATENTEDAPR slen 31573415 SHEET 3 BF 6 PATENTEYD APR 6 I97! SHEET 6 OF 6 PARALLEL POLE CIRCUIT BREAKER This invention relates to circuit breakers in general, and more particularly relates to means for paralleling the poles of single-pole circuit breakers.

Prior art parallel-pole circuit breakers cannot be used as branch circuit breakers in a panelboard or load center without very special precautions being taken. For the most part the prior art achieves paralleling of single-pole circuit breakers by utilizing jumper connections externally of the circuit breakers. In such manner it is possible to adapt single-pole units of the prior art for parallel operation for single-phase service by connecting alternate poles at their load ends. However, such parallel arrangement is unsuitable for three phase panclboards since phase-to-phase shorts would result.

Accordingly, a primary object of the instant invention is to provide a parallel-pole circuit breaker that may be used in either a single-phase or three-phase panelboard.

Another object is to provide two pair of single-pole circuit breakers, with the circuit breakers of each pair being connected in parallel and having line terminal connecting means to cooperate and connect into both single-phase and threephase panelboards.

Still another object is to provide two pair of parallel-pole circuit breakers, with a wire grip housing so constructed that the individual circuit breaker load terminal connections may not be tampered with.

A further object is to provide two pair of parallel-pole circuit breakers in which each pair is provided with a line terminal stab portion inside the circuit breaker housing and a line terminal stab extension portion disposed externally of the housing.

Thse objects as well as other objects of this invention will become readily apparent after reading the following description of the accompanying drawings in which:

FIG. I is a cross secton of four single-pole circuit breakers in stacked relationship and electrically paralleled in. accordance with teachings of the instant invention.

FIG. 2 is a line end view looking in the direction of arrows 2-2 of FIG. 1.

FIG. 3 is a plan view looking in the direction of arrows 3-3 of FIG. 1.

FIGS. 4 and 5 are fragmentary cross sections taken through lines 44 and 5-5.

FIG. 6 is a side elevation of a load end paralleling strap.

FIG. 6A is aplan .view of the strap of FIG. 6.

FIG. 6B is an elevation of the strap of FIG. 6, looking in the direction of arrows 6B, 6B.

FIG. 7 is a side elevation of a line terminal assembly.

FIG. 7A is a bottom view of the assembly of FIG. 7, looking in the direction of arrows 7A-7A.

FIG. 7B isan end view of the assembly of FIG. 7, looking in the direction of arrows 7B-7B.

FIG. 8 is a perspective, partially exploded, of the assembly of FIG. 7.

FIG. 9 is a rear elevation of the housing for the load end wire grips.

FIGS. 9A, 9B and 9C are cross sections taken through the respective lines 9A-9A, 93-98 and 9C-9C, looking in the directions of the respective arrows 9A, 9A; 9B, 9B; and 9C,

FIG. 9D is a front elevation of a housing of FIG. 9.

FIG. 9E is a plan view of the housing looking in the direction of arrows 9e, 9e of FIG. 9D.

Now referring to the FIGS. The assembly indicated generally by reference numeral 10 in FIGS. 2 and 3 consists of a. stack of four single-pole circuit breakers or pole units l1- -l4 stacked together in side-by-side relationship and secured in position by four rivets 15. With minor variation, each of the circuit breakers l114 is of identical construction and is of a type described in detail in the F. E. Myers US Pat. No. 2,996,589 issued Aug. l5, l96l for a Pivoted Bimetal. As will hereinafter be seen, circuit breakers II and 12 are electrically connected at both teeir line and load ends. Similarly, circuit breakers l3 and 14 are electrically connected at both their line and load ends. Rivet l6 and U-shaped cap 17 mechanically connect operating handles 18 of all four circuit breakers 11-14 together for simultaneous manual operation.

Briefly, with particular reference to FIG. I, the current path through the single pole constituting circuit breaker 13 consists of load terminal 21, flexible braid 22, bimetal 23, its L-shaped extension 24, flexible braid 25, movable contact element 26, movable contact 27, stationary contact 28 and female-type line terminal stab 31 and portion 32 thereof. Terminal 31 is part of line terminal assembly 35, illustrated in FIGS. 7, 7A, 7B and 8.

In particular, assembly 35 includes first conducting member 36 havingjumper portion 37 which extends between the housings for circuit breakers l3 and 14. The downturned portion. of member 36 at the left end of strap 37 in FIG. 8 is formed to constitute one arm of the stab portion that is disposed within housing 33 of circuit breaker I3 and is also formed to constitute both legs of the U-shaped stab constituting stab portion 32 which extends outside the housing of circuit breaker 13. The other leg portion of stab terminal 31 which is disposed within the housing of circuit breaker 13 consists of the downwardly bent formation 38 at the left end of the other conducting member 39 of line terminal assembly 35. Strap portion 41 is welded to the lower surface of strap portion 37. Stationary contacts 28 and 42 are welded to the respective ears 43, 44, positioned along one'edge'of strap portion 36 and extending downwardly therefrom. It is noted that contact 42 is the stationary contact for pole unit 14. Fan-shaped arc runner 45 is secured to the tab 43 at the rear thereof.

Insulating tape 46 is wrapped around the central portions of straps 36, 41 to bridge the gap between aligned casing openings through which line terminal assembly 35 extends. U- shaped spring 47 (FIG. 1) provides contact pressure between the stab jaw portions within casing 33, while another U-shaped spring 48 provides contact pressure for the stab jaws external to casing 33. Stab 31 extends through line side opening 49, disposed at the lower lefthand corner of the housing for circuit breaker 13, as viewed in FIG. I. The corresponding openings 49 in circuit breaker 14 is closed off by an appropriately shaped insulating block 51 which is notched at 51a (FIG. 2) to accommodate a panelboard bus connected male stab without making electrical connections to any of the circuit breakers l Il4.

Another line terminal assembly 52, constructed as a mirror image of line terminal assembly 35, extends between the casings of circuit breakers I1 and 12, to electrically interconnect the stationary contacts of these breakers. Thus, stab portion 53, corresponding to stab portion 31, protrudes through the line and opening 49 in the casing of circuit breaker 12, while another insulating block SI effectively closes off the corresponding line side opening 49 in the casing of circuit breaker ll.

Insulating barrier 99 is inerposed between extending stab portions 32, 32 of line terminal assemblies 35 and 52 to prevent phase tp phase flashover. Barrier 99 extends into a cavity formed by the cooperation of protrusions in the adjacent sidewalls of pole units 12 and 13 and is retained by certain of these protrusions, as well as being cemented to the housing of either pole unit 12 or I3.

Load terminals 21 of circuit breakers l3 and 14 are electrically interconnected by load tenninal assembly 60, which is most clearly illustrated in FIGS. 6, 6A and 6B. In particular, assembly 60 includes planar terminal portion 61, having an upwardly extending S-shaped portion 62 along one edge thereof. Parallel extensions 63, 64 at opposite ends of portion- 62 rest against the upper surfaces of load terminals 21 for circuit breakers l3 and 14, with screws 66 of wire grips 65 for circuit breakers 13 and 14 providing clamping pressure between extensions 63, 64 and load terminals 21. Terminal portion 61 is provided with threaded aperture 67 for the securement of wire grip 68 (FIG. 3). Screw 69 secures spring retainer 70 to the upper surface of terminal portion 61.

Load terminal assembly 72, identical in construction to load terminal assembly 60,, electrically interconnects the load terminals 21 of circuit breakers 11 and 12. Wire grip 73 secured to load terminal assembly 70 provides means for connecting a load conductor to the parallel combination of circuit breakers 11 and 12. 7

Molded insulating housing 75 is placed in operative position abutting the load end of all four circuit breaker housings by movement from right to left with respect to FIGS. l3. Movement of housing 75 in the opposite direction is prevented by spring retainers 70 which, after being depressed toward terminal portions 61, spring upward to positions behind shoulder formations 76 (FIG; 1) of housing 75. hits operative position, formations of housing 75 prevent access to clamping screws 66, so that the connection to circuit breaker load terminals 2] cannot be tampered with. Other formations of housing 75 provide recesses 78 for wire grips 68, 73 and still other formations of housing 75 serve to position and/or enclose other sections of assemblies 60, 60. As seen in FIG. 3, wire grip 68 is in line with the abutting sides of pole units l3, l4 and wire grip 73 is in line with the abutting sides of pole units ll, 12.

Thus, it is seen that the instant invention provides a doublepole breaker assembly inwhich each pole consists of two adjacent pole units connected in electrical parallel. The line terminals of the poles are spaced apart by the center-to-center distance between adjacent pole units so that the assembly may be plugged into either a single or three-phase panelboard. Each line terminal includes an extension which prevents additional pole units from being connected to a panelboard stab with which an assembly stab is connected.

Although there have been described preferred embodiments of this novel invention, many variations and modifications will now be apparent to those skilled in the art. Therefore, this invention is to be limited not by the specific disclosure herein, but only by the appending claims.

lclaim:

I. In combination, a plurality of pole units stacked side by side with a first and a second of said pole units being adjacent to each other, a third and a fourth of said pole units including a stationary contact, a movable contact, a mechanism for. operating said contacts into and out of engagemenna casing wherein said contacts and mechanism are disposed,- an operating handle for said mechanism extending through afforward opening in said casing, and a terminal at the load end of said casing; a first line terminal assembly extending into said casings of said first and second pole units and including the stationary contacts thereof; a second line terminal assembly extending into said casings of said third and fourth pole units and including the stationary contacts thereof; said first and second assemblies at the line ends of their respective casings including respective first and second line terminals; said first and second line terminals located on centers spaced apart by a distance equal to the distance between centers of adjacent ones of said pole units; a first load terminal assembly having portions connected to said load terminals of said first and second pole units and a second load terminal assembly having portions connected to said third and fourth pole units; said first and second load terminal assemblies including respective first and second wire grips; said first and second wire grips located on centers spaced apart by a distance equal to twice the distance between centers of adjacent ones of said pole units.

2. A combination as set forth in claim 1 in which said first and second line terminals are each proportioned to engage a single-pole unit energizing location of a panelboard; said first and second line terminals having respective first and second extensions; each of said line terminals together with its said extension engaging two adjacent pole unit energizing locations of a panelboard.

3. A combination as set and second line terminals are disposed within the casings of said second and third pole units, respectively, and said first and second extensions are disposed externally thereof,

4..A combination asset forth in claim 3 including a barrier extending from the junction between the casings of said second and third pole units and positioned between said extensions.

5. A combination as set forth in claim 1 including a housing wherein said wire grips are disposed.

6. A combinaton as set forth in claim 5 in which there are screw-type connections connecting said load terminals to said portions of said load terminal assemblies; with said housing mounted in operative position sections thereof concealing said screw-type connections.

7. A combination as set forth in claim 6 in which there is a snap-on-type connecting means securing said housing in operative position.

8. A combination as set forth in claim 7 in which said snapon-type connecting means includes spring elements on said terminal assemblies.

9. A combination as set forth in claim 8 in which said first wire grip is positioned opposite the intersection of said first and second pole units and'said second wire grip is positioned opposite'the intersection of said third and fourth pole units.

10. A combination as set forth in claim 9 in which said first and second line terminals are each proportioned to engage a single-pole unit energizing location of a panelboard; said first and second line terminals having respective first and second extensions; each of said line terminals together with its said extension engaging two adjacent pole unit energizing locations of a panelboard; said first and second line terminals disposed within the casings'of said second and third pole units, respectivcly, and said first and second extensions are disposed externally thereof.

forth in claim 2 in which said first 

1. In combination, a plurality of pole units stacked side by side with a first and a second of said pole units being adjacent to each othEr, a third and a fourth of said pole units including a stationary contact, a movable contact, a mechanism for operating said contacts into and out of engagement, a casing wherein said contacts and mechanism are disposed, an operating handle for said mechanism extending through a forward opening in said casing, and a terminal at the load end of said casing; a first line terminal assembly extending into said casings of said first and second pole units and including the stationary contacts thereof; a second line terminal assembly extending into said casings of said third and fourth pole units and including the stationary contacts thereof; said first and second assemblies at the line ends of their respective casings including respective first and second line terminals; said first and second line terminals located on centers spaced apart by a distance equal to the distance between centers of adjacent ones of said pole units; a first load terminal assembly having portions connected to said load terminals of said first and second pole units and a second load terminal assembly having portions connected to said third and fourth pole units; said first and second load terminal assemblies including respective first and second wire grips; said first and second wire grips located on centers spaced apart by a distance equal to twice the distance between centers of adjacent ones of said pole units.
 2. A combination as set forth in claim 1 in which said first and second line terminals are each proportioned to engage a single-pole unit energizing location of a panelboard; said first and second line terminals having respective first and second extensions; each of said line terminals together with its said extension engaging two adjacent pole unit energizing locations of a panelboard.
 3. A combination as set forth in claim 2 in which said first and second line terminals are disposed within the casings of said second and third pole units, respectively, and said first and second extensions are disposed externally thereof.
 4. A combination as set forth in claim 3 including a barrier extending from the junction between the casings of said second and third pole units and positioned between said extensions.
 5. A combination as set forth in claim 1 including a housing wherein said wire grips are disposed.
 6. A combinaton as set forth in claim 5 in which there are screw-type connections connecting said load terminals to said portions of said load terminal assemblies; with said housing mounted in operative position sections thereof concealing said screw-type connections.
 7. A combination as set forth in claim 6 in which there is a snap-on-type connecting means securing said housing in operative position.
 8. A combination as set forth in claim 7 in which said snap-on-type connecting means includes spring elements on said terminal assemblies.
 9. A combination as set forth in claim 8 in which said first wire grip is positioned opposite the intersection of said first and second pole units and said second wire grip is positioned opposite the intersection of said third and fourth pole units.
 10. A combination as set forth in claim 9 in which said first and second line terminals are each proportioned to engage a single-pole unit energizing location of a panelboard; said first and second line terminals having respective first and second extensions; each of said line terminals together with its said extension engaging two adjacent pole unit energizing locations of a panelboard; said first and second line terminals disposed within the casings of said second and third pole units, respectively, and said first and second extensions are disposed externally thereof. 